1. Field of the Invention
The invention relates to drive circuits.
2. Description of Prior Art
The invention relates more particularly to a drive circuit for use in controlling a lamp driven by solar cells. Such lamps are used for all forms of lighting applications, especially exterior light around dwelling places. The lamps are arranged to be driven by rechargeable batteries provided with solar panels so that they rely mainly or solely on receiving charging current generated by the solar cells during day light hours.
Commonly a fluorescent tube or lamp is used and driven via an electronic ballast. Battery energy is used to provide a high frequency high voltage power source which is applied between the terminals of the lamp. The ballast consists of a multi-phase transformer with a free-running oscillator.
At present the lamps that are known or that have been proposed are relatively inefficient in terms of power consumption, and the working life of the lamp tends to be limited due to poor control of the power supply to the lamp.